Vitamin B6 and cancer risk across many studies
What it found
In people, eating more vitamin B6 from food was linked to lower cancer risk, especially gut cancers.
But trials giving vitamin B6 did not show a protective effect.
What they found
Studies in people
Food vitamin B6 and cancer
High intake of vitamin B6 from food only was linked to lower risk of all cancers. The link was strongest for gastrointestinal carcinomas.
Blood PLP and cancer
High blood levels of PLP, the active form of vitamin B6, were also linked to lower risk of all cancers. The most consistent results were for gastrointestinal tumors.
Dose-response relationship
There was a straight-line link between cancer risk and both vitamin B6 from food and PLP levels. As intake or levels went up, risk went down.
Total intake weaker
When vitamin B6 from food and supplements was combined, the links were weaker or absent.
Trials show no protection
Randomized controlled trials did not support a protective effect of vitamin B6 against cancer. The authors graded this evidence as low level.
What the authors conclude
“Epidemiological evidence supports the potential of vitamin B6 as a cancer risk reduction agent and the role of PLP as a cancer screening biomarker, especially for gastrointestinal tumors.”
Also in their conclusions
- They say the epidemiological evidence supports the potential of vitamin B6 as a cancer risk reduction agent and the role of PLP as a cancer screening biomarker, especially for gastrointestinal tumors.
- They note that inconsistent findings from total intake and intervention studies suggest that vitamin B6 might also be an indicator of other dietary protective micronutrients.
How it was done
Vitamin B6 takes part in many chemical reactions in the body and might play a role in how cancers start. The authors pulled together the evidence linking vitamin B6 to cancer risk.
They reviewed 121 observational studies with 1 924 506 participants and 96 436 cancer cases, plus nine randomized controlled trials with 34 911 participants and 2539 cases, covering 19 tumor sites. They compared high versus low vitamin B6 intake or blood PLP levels, and also looked at dose-response.
What it can’t tell you
- We summarised it from the abstract only.
- The observational studies can show a link between vitamin B6 and cancer risk, but they cannot prove that vitamin B6 causes the lower risk.
- The trials did not find a protective effect, so it is unclear whether vitamin B6 itself reduces cancer risk or is just a marker of other protective nutrients.
Who paid
- Authors work at
- University of Padova, Italy
The paper
- Title
- Vitamin B6 and Cancer Risk: A Field Synopsis and Meta-Analysis
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Mocellin S, Briarava M, Pilati P (2017). Vitamin B6 and Cancer Risk: A Field Synopsis and Meta-Analysis. Journal of the National Cancer Institute. doi:10.1093/jnci/djw230PubMed 28376200DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error